Accommodating intraocular lenses

ABSTRACT

Accommodating intraocular lenses containing a flowable media and their methods of accommodation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/193,983, filed Jul. 29, 2011, which is a continuation of U.S.application Ser. No. 12/177,857, filed Jul. 22, 2008, now U.S. Pat. No.8,328,869, which claims the benefit of U.S. Provisional Application No.60/951,447, filed Jul. 23, 2007, each of which is incorporated byreference herein.

BACKGROUND

Cataracts are a major cause of blindness in the world and the mostprevalent ocular disease. When the disability from cataracts affects oralters an individual's activities of daily living, surgical lens removalwith intraocular lens (“IOL”) implantation is the preferred method oftreating the functional limitations.

A cataract is any opacity of a patient's lens, whether it is a localizedopacity or a diffuse general loss of transparency. To be clinicallysignificant, however, the cataract must cause a significant reduction invisual acuity or a functional impairment. A cataract occurs as a resultof aging or secondary to hereditary factors, trauma, inflammation,metabolic or nutritional disorders, or radiation. Age-related cataractconditions are the most common.

In treating a cataract, the surgeon removes the crystalline lens matrixfrom the lens capsule and replaces it with an IOL. The typical IOLprovides a selected focal length that allows the patient to have fairlygood distance vision. Since the lens can no longer accommodate, however,the patient typically needs glasses for reading.

More specifically, the imaging properties of the human eye arefacilitated by several optical interfaces. A healthy youthful human eyehas a total power of approximately 59 diopters, with the anteriorsurface of the cornea (e.g. the exterior surface, including the tearlayer) providing about 48 diopters of power, while the posterior surfaceprovides about −4 diopters. The crystalline lens, which is situatedposterior of the pupil in a transparent elastic capsule, also referredto herein as “capsular sac,” supported by the ciliary muscles viazonules, provides about 15 diopters of power, and also performs thecritical function of focusing images upon the retina. This focusingability, referred to as “accommodation,” enables imaging of objects atvarious distances.

The power of the lens in a youthful eye can be adjusted from 15 dioptersto about 29 diopters by adjusting the shape of the lens from amoderately convex shape to a highly convex shape. The mechanismgenerally accepted to cause this adjustment is that ciliary musclessupporting the capsule (and the lens contained therein) move between arelaxed state (corresponding to the moderately convex shape) and acontracted state (corresponding to the highly convex shape). Because thelens itself is composed of viscous, gelatinous transparent fibers,arranged in an “onion-like” layered structure, forces applied to thecapsule by the ciliary muscles via the zonules cause the lens to changeshape.

Isolated from the eye, the relaxed capsule and lens take on a morespherical shape. Within the eye, however, the capsule is connectedaround its circumference by approximately 70 tiny ligament fibers to theciliary muscles, which in turn are attached to an inner surface of theeyeball. The ciliary muscles that support the lens and capsule thereforeare believed to act in a sphincter-muscular mode. Accordingly, when theciliary muscles are relaxed, the capsule and lens are pulled about thecircumference to a larger diameter, thereby flattening the lens, whereaswhen the ciliary muscles are contracted the lens and capsule relaxsomewhat and assume a smaller diameter that approaches a more sphericalshape.

As noted above, the youthful eye has approximately 14 diopters ofaccommodation. As a person ages, the lens hardens and becomes lesselastic, so that by about age 45-50, accommodation is reduced to about 2diopters. At a later age the lens may be considered to benon-accommodating, a condition known as “presbyopia”. Because theimaging distance is fixed, presbyopia typically entails the need forbi-focals to facilitate near and far vision.

Apart from age-related loss of accommodation ability, such loss isinnate to the placement of IOLs for the treatment of cataracts. IOLs aregenerally single element lenses made from a suitable polymer material,such as acrylics or silicones. After placement, accommodation is nolonger possible, although this ability is typically already lost forpersons receiving an IOL. There is significant need to provide foraccommodation in IOL products so that IOL recipients will haveaccommodating ability.

Although efforts have been made with accommodating IOLs, there is a needfor an accommodating IOL that can restore as much accommodation to theeye as possible.

SUMMARY OF THE DISCLOSURE

One aspect of the invention is an accommodating intraocular lens. Thelens includes an optic portion comprising an anterior element, aposterior element, and an intermediate layer disposed along an opticalpath of the lens, wherein the intermediate layer is disposed between theanterior element and the posterior element. The lens also includes aperipheral portion in fluid communication with the optic portion. Theintraocular lens is adapted such that when a flowable media is movedbetween the peripheral portion and the optic portion in response tociliary muscle movement, at least two of the anterior element, theposterior element, and the intermediate layer move from a firstconfiguration to a second configuration.

In some embodiments the posterior element comprises a channel formedtherein, and wherein the posterior element and the intermediate layerdefine an active channel in fluid communication with the peripheralportion. The anterior element can be bonded to the intermediate layer,such as along the periphery of the anterior layer. The intermediatelayer can also be bonded to the posterior element.

In some embodiments the intermediate layer comprises an actuator. Theactuator can be in contact with the anterior element throughout anentire accommodation range of the intraocular lens, or the actuator maynot be in contact with the anterior element throughout an entireaccommodation range of the intraocular lens. The actuator assumes asubstantially conical configuration in a disaccommodated configuration.

In some embodiments the peripheral portion is coupled to the posteriorelement. The posterior element can include a buttress element disposedat the periphery of the posterior element, and wherein the peripheralportion is coupled to the buttress element. The peripheral portion cancomprises a haptic and the haptic comprises a connection element adaptedto fit within a bore in the buttress element. The peripheral portion cancomprise a haptic and the buttress element comprises a connectionelement adapted to fit within a bore in the haptic.

In some embodiments the intermediate layer and the anterior elementdefine a passive chamber containing a second flowable media therein. Theanterior element, the intermediate layer, the posterior element, thesecond flowable media, and the flowable media can all be substantiallyindexed matched to one another.

In some embodiments the at least two of the anterior element, theposterior element, and the intermediate layer that move from a firstconfiguration to a second configuration are the intermediate layer andthe anterior element.

One aspect of the invention is an accommodating intraocular lens. Thelens includes an optic portion comprising an anterior element, aposterior element, and an intermediate layer disposed between theanterior element and the posterior element. An anterior surface of theanterior element defines an anterior surface of the lens and a posteriorsurface of the posterior element defines a posterior surface of thelens. The lens also includes a peripheral portion in fluid communicationwith the optic portion. The intraocular lens is adapted such that when aflowable media is moved between the optic portion and the peripheralportion in response to ciliary muscle movement, at least one of theanterior surface of the lens and the posterior surface of the lens movesfrom a first configuration to a second configuration.

In some embodiments a first surface of the intermediate layer partiallydefines an active channel which is in fluid communication with theperipheral portion. The intermediate layer and the posterior element candefine the active channel. The intermediate layer and the anteriorelement can define a passive chamber containing a second flowable media.In some embodiments the anterior element, the posterior element, theintermediate layer, the flowable media, and the second flowable mediaall are substantially index-matched to each other.

In some embodiments the anterior element is bonded to the intermediatelayer, which can be along the periphery of the anterior layer. Theintermediate layer can be bonded to the posterior element.

In some embodiments the intermediate layer comprises an actuator, whichcan be in contact with the anterior element throughout an entireaccommodation range of the intraocular lens, or which can be in contactwith the anterior element only through a portion of an entireaccommodation range of the intraocular lens. The actuator can assume asubstantially conical configuration in a disaccommodated configuration.

In some embodiments the peripheral portion is coupled to the posteriorelement. The posterior element can include a buttress element disposedat the periphery of the posterior element, and the peripheral portion iscoupled to the buttress element. The peripheral portion can comprises ahaptic and the haptic comprises a connection element adapted to fitwithin a bore in the buttress element. The buttress element canalternatively comprise a connection element adapted to fit within a borein the haptic.

One aspect of the invention is a method of changing an optical parameterof an accommodating intraocular lens. The method includes providing anintraocular lens comprising an optic portion and a peripheral portionextending peripherally from the optic portion, wherein the optic portioncomprises an anterior element, a posterior element, and an intermediatelayer disposed between the anterior element and the posterior element.The optic portion and the peripheral portion are in fluid communication.The method also includes moving a flowable media between the opticportion and the peripheral portion in response to ciliary musclemovement to change an optical parameter of the intraocular lens, whereinmoving a flowable media between the optic portion and the peripheralportion comprises moving at least two of the anterior element, theintermediate layer, and the posterior element from a first configurationto a second configuration.

In some embodiments moving a flowable media between the optic portionand the peripheral portion comprises deforming the peripheral portion.Moving at least two of the anterior element, the intermediate layer, andthe posterior element can comprise moving the intermediate layer and theanterior element from a first configuration to a second configuration.

In some embodiments the intermediate layer and the posterior elementdefine an active channel in fluid communication with the peripheralportion, and the intermediate layer and the anterior element define apassive chamber containing a second flowable media therein. The methodfurther comprising index matching the anterior element, the intermediatelayer, the posterior element, the second flowable media, and theflowable media.

One aspect of the invention is a method of changing the power of anaccommodating intraocular lens. The method includes providing anintraocular lens including an optic portion and a non-optic peripheralportion, wherein the optic portion comprises an anterior element, aposterior element, and an intermediate layer disposed between theanterior element and the posterior element, and wherein an anteriorsurface of the anterior element defines an anterior surface of theintraocular lens, and wherein a posterior surface of the posteriorelement defines a posterior surface of the intraocular lens. The methodalso includes moving a flowable media between the optic portion and thenon-optic portion in response to ciliary muscle movement to change thepower of the intraocular lens, wherein moving a flowable media betweenthe optic portion and the non-optic portion comprises moving at leastone of the anterior surface of the intraocular lens and the posteriorsurface of the intraocular lens.

In some embodiments moving a flowable media between the optic portionand the non-optic portion comprises deforming the non-optic portion.Moving a flowable media between the optic portion and the non-opticportion can comprise moving the intermediate layer from a firstconfiguration to a second configuration.

In some embodiments the intermediate layer and the posterior elementdefine an active channel in fluid communication with the peripheralportion, and the intermediate layer and the anterior element define apassive chamber containing a second flowable media therein. The methodalso includes index matching the anterior element, the intermediatelayer, the posterior element, the second flowable media, and theflowable media.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIGS. 1, 2A, and 2B illustrate the structure and operation of a humaneye.

FIGS. 3-5 show an exemplary embodiment of an intraocular lens.

FIG. 6 shows a portion of an exemplary intraocular lens indisaccommodative and accommodative configurations.

FIG. 7 shows an exemplary optic portion of an intraocular lens.

FIGS. 8A-8C show an alternative embodiment of an intraocular lens.

FIGS. 9-12 show an alternative embodiment of an intraocular lens.

FIGS. 13-15 show an alternative embodiment of an intraocular lens invarying accommodative configurations.

FIG. 16 shows an exemplary haptic being compressed between a lenscapsule and an optic portion.

FIGS. 17-20 show exemplary alternative haptic designs.

FIG. 21 illustrates dimensions of an exemplary haptic.

FIG. 22 shows an exemplary haptic design and a capsule in accommodatedand disaccommodated configurations.

FIGS. 23 and 24 show an alternative haptic design comprising bellows.

DETAILED DESCRIPTION

The invention relates generally to intraocular lenses (“IOLs”) andparticularly to accommodating intraocular lenses. In preferredembodiments the IOL includes a flowable media (such as a fluid,gelatinous material, etc.) that is moved within the IOL, in response tociliary muscle movement, to change the power of the IOL.

FIGS. 1 and 2 illustrate the structure and operation of a human eye. Eye100 includes cornea 1, iris 2, ciliary muscles 3, ligament fibers orzonules 4, capsule 5, lens 6 and retina 7. Natural lens 6 is composed ofviscous, gelatinous transparent fibers, arranged in an “onion-like”layered structure, and is disposed in transparent elastic capsule 5.Capsule 5 is joined by zonules 4 around its circumference to ciliarymuscles 3, which are in turn attached to the inner surface of eye 0.Vitreous 8 is a highly viscous, transparent fluid that fills the centerof eye 100.

Isolated from the eye, the relaxed capsule and lens take on a convexshape. However, when suspended within the eye by zonules 4, capsule 5moves between a moderately convex shape (when the ciliary muscles arerelaxed) and a highly convex shape (when the ciliary muscles arecontracted). As shown in FIG. 2A, when ciliary muscles 3 relax, capsule5 and lens 6 are pulled about the circumference, thereby flattening thelens. As shown in FIG. 2B, when ciliary muscles 3 contract, capsule 5and lens 6 relax and become thicker. This allows the lens and capsule toassume a more convex shape, thus increasing the diopter power of thelens.

Additionally, various natural mechanisms affect the design requirementsof the present invention. For example, during accommodation the pupilnaturally stops down (i.e., reduces in diameter) which reduces the areaof the natural lens that transmits light. In addition, the eye willexperience the Stiles-Crawford Effect which also reduces the effectivearea of the natural lens. In particular, the brightness of light raysincident on cones in the eye is dependent on the angle at which thoserays are incident on the cones. In particular, light rays that strikethe cones perpendicular to their surface appear brighter than those thatdo not. As a result, the light rays passing through the periphery of thelens are less significant for proper vision.

FIGS. 3-5 show a first embodiment of accommodating IOL 10. IOL 10includes a peripheral non-optic portion comprising haptics 12 and 14.The IOL also includes an optic portion including anterior lens element16, intermediate layer 18 which comprises actuator 20, and substrate, orposterior element, 22. Anterior element 16 is bonded to intermediatelayer 18 at its periphery. In some embodiments the anterior element mayalso be bonded to actuator 20. The intermediate layer is also bonded toposterior element 22. The inner surface of haptics 12 and 14 defineinterior volumes 24 which are in fluid communication with active channel26 defined by posterior element 22 and intermediate layer 18. As shown,actuator 20 is integral with intermediate layer 18. Posterior element 22is molded with buttresses 11 which include a buttress bore 13therethrough. The haptics have a haptic attachment element 15 (which canbe stiff or flexible) which is sized and shaped to fit within buttressbore 13. An adhesive layer can be applied to the outer surfaces of thehaptic attachment elements and/or the inner surface of the buttress boreto facilitate attachment of the haptics to the optic portion. The IOLcontains a flowable media within the haptics and the active channel. TheIOL also includes passive chamber 21 that is defined by the anteriorelement and the intermediate layer. The passive chamber contains asecond flowable media (e.g., a fluid, elastomer, etc.), which may be thesame as the fluid within the haptics and active channel, or it may be adifferent flowable media. The active channel and the passive chamber arenot in fluid communication.

Deformation of haptics 12 and 14 in response to contraction of ciliarymuscles movement transfers the flowable media (such as a fluid) betweeninterior volume 24 and active channel 26. When the flowable media istransferred into the active channel from the haptics, the pressure inthe active channel increases, causing actuator 20 to deflect in theanterior direction. This causes anterior element 16 to deflect in theanterior direction, increasing the IOL power in this accommodatedconfiguration.

In any of the embodiments herein, moving fluid between the haptics andthe optic portion can cause the change in curvature of the posteriorelement rather than, or in addition to, the anterior element. Whilechanging the curvature of the anterior element is described herein, thisis not meant to be limiting to the IOLs. For example, the IOL can beflipped upon implantation such that the anterior element is disposed onthe posterior side of the lens, while the posterior element is disposedon the anterior side of the lens. Moving fluid from the haptics to theoptics would therefore cause the posterior surface of the IOL deflect.Alternatively, the actuator can be in contact with the posterior elementand the active channel can be defined by the intermediate layer and theanterior element, while the passive chamber is defined by the posteriorelement and the intermediate layer. Moving fluid from the haptics to theactive channel would thereby deflect the posterior element.

FIG. 6 is a cross sectional view of a section of an exemplary IOLshowing the IOL in a disaccommodated state (dashed lines) and anaccommodated state (solid lines). The IOL includes anterior element 74,intermediate layer 78 which includes actuator 73, and posterior element75. Actuator 73 is comprised of deflection element 71 and bellows 70.When the pressure is increased in active channel 72, bellows 70 changeconfiguration from the generally conical shape of the disaccommodatedstate to a curvilinear configuration of the accommodated state.Deflection element 71 is forced in the anterior direction due to theincrease in pressure. This causes anterior element 74 to deflect in theanterior direction as well, steepening the curvature of the anteriorelement and thereby increasing the power of the lens.

All of the components of the optic portion, including the activeflowable media and the passive flowable media, can be substantiallyindex-matched to provide for a generally singular lens element definedby the anterior surface of the anterior element and the posteriorsurface of the posterior element. “Substantially index-matched” as usedherein refers to an IOL whose components are intended to have the sameindex of refraction, but whose actual indices may differ slightly. Theterm also refers to a lens which can have adhesive (to bond differentcomponents of the lens together) which may have an index of refractionthat is slightly different than the indices of the other IOL components.

Some of the components may, however, have different indices ofrefraction, creating additional interfaces within the IOL.

FIG. 7 is a cross sectional view of an IOL (haptics not shown) similarto that shown in FIGS. 3-5. FIG. 7 illustrates exemplary dimensions ofthe optic portion of the IOL. Anterior element diameter 30 is about 6.0mm. The anterior element thickness 31 at the center of the anteriorelement is about 0.43 mm. Intermediate layer edge thickness 32 is about0.35 mm. Intermediate layer center thickness 33 (i.e., deflectionelement center thickness) is about 0.63 mm. Bellows length 40 is about1.0 mm. Bellows thickness 34 is about 0.10 mm. Actuator diameter 35 isabout 3.40 mm. Posterior element edge thickness 36 is about 0.60 mm.Posterior element center thickness 37 is about 0.70 mm. Posteriorelement diameter 38 can be about 6.6 mm to about 7.4 mm. The IOL centerthickness 39 (in the disaccommodated configuration) between the anteriorsurface of the anterior element and posterior surface of the posteriorelement along the optical axis of the lens is about 1.8 mm to about 2.2mm.

Bellows thickness 34 can be adjusted to change the responsiveness of theactuator. As the thickness of the bellows decreases, less fluid pressureis generally required to displace the actuator. In some embodiments thebellows thickness is between about 0.05 mm and about 0.3 mm.

Decreasing the anterior element thickness 31 generally increases theresponsiveness of the actuator for a given fluid pressure. Length ofbellows 40 can also be adjusted to alter the responsiveness of theactuator (actuator diameter 35 can similarly be adjusted). As the lengthof the bellows increases, the volume of the active channel is increasedand more volume of flowable media is required to move the actuator.However, by increasing the bellows length, the pressure in the activechannel is decreased. Therefore, the volume and pressure required todrive the actuator can be optimized in combination with the flowablemedia transferred from the haptics to provide the greatest response.

In some embodiments the length of the bellows is between about 1 mm and2 mm. In some embodiments actuator diameter 35 is between about 2.8 mmand about 4.2 mm.

The dimensions given above are merely exemplary and not intended to belimiting.

FIGS. 8A-8C show an additional embodiment of IOL 401. IOL 401 includesanterior element 404, intermediate layer 402, posterior element 400, andhaptics 412. Intermediate layer 402 comprises an actuator, whichcomprises deflection element 406 and bellows 408. Also shown are passivechamber 405 and active channel 410. As can be seen in FIGS. 8B and 8C,anterior element 404 and intermediate layer 402 are bonded directly toposterior element 400, which removes an intermediate assembly step ofcoupling the intermediate layer 402 to the anterior element 404 (as isthe construction in the embodiment shown in FIGS. 3-5). Anterior element404 and intermediate layer 402 are both bonded to posterior element 400along their periphery. Anterior element 404 is bonded to posteriorelement 400 at a location more radially outward from the optical axis OAthan is intermediate layer 402.

The amount of shape change (i.e., the change in curvature) that theanterior element will undergo in response to fluid movement between theperipheral portion and the optic portion will depend partially on howand where the anterior element is bonded to either the intermediatelayer or the posterior element. By varying these boundary conditions itis possible to change the optic power shift for a given amount ofdisplacement at the center of the lens. For example, an anterior elementbonded at the very edge of its periphery will deflect in a morespherical manner than will an anterior element that is bonded moreradially inward than merely at its periphery. The former is allowed toflex all the way out to its periphery, while the latter is moreconstrained when deflected and will assume a less sphericalconfiguration when in an accommodated configuration (i.e., will have astronger aberration).

In addition, the lens bonded at its periphery will deflect at loweractive channel pressures than will a lens that is bonded closer to thecenter.

The anterior element is attached to the posterior element at surface 417of the posterior element. This mating surface is substantiallyorthogonal to the optical axis OA. This helps with the assembly process,and gives anterior element 404 a firm foundation on which to sit. FIG.8C shows a cross sectional perspective view including haptics 412.

The posterior element in FIG. 8A includes buttresses 411. Buttresses 411include nipples 413 which are adapted to fit within haptic bore 415 toattach the haptics to the posterior element. Adhesive can be applied tothe mating surfaces.

FIGS. 9-12 show an alternative embodiment of IOL 200. IOL 200 includesanterior element 202, intermediate layer 204, posterior element 206, andhaptics 208. The haptics are attached to the intermediate layer 204 byattaching buttress elements 212 with optic buttresses 210. The actuatorincludes deflection element 213 and bellows 215. FIG. 12 is a top viewshowing the haptics (optic portion not shown). As can be seen, hapticbuttress element 212 is incorporated into haptic 208 and attaches to theoptic portion at optic buttress 210. One difference in this embodimentis that most of the mechanical complexity is incorporated into onecomponent of the lens—the intermediate layer. Because the hapticsincorporate a buttress element, the change in direction (roughly 90degrees) of the flowable media occurs in the haptic buttress elementrather than in an optic buttress as is the case in the embodiments shownin FIGS. 3-5 and FIGS. 8A-8C.

FIGS. 13-15 illustrate an alternative embodiment in which deflectionelement 312 of the intermediate layer is not in contact with anteriorelement 302 during the entire accommodation motion of the lens. FIG. 13shows IOL 300 in a disaccommodated state including anterior element 302,intermediate layer 304 (including deflection element 312 of theactuator), and posterior element 306. The IOL includes gap 310 betweenthe deflection element and the anterior element. When there is nopressure in active channel 308 or in passive chamber 314 (as shown inFIG. 13), the geometry and passive fluid state is such that there is gap310 between the deflection element and the anterior element.

As the pressure in active channel 308 increases (due to movement of thecapsular bag), deflection element 312 moves in the anterior direction.Because of the pressure transfer into passive chamber 314, anteriorelement 302 also moves in the anterior direction (thus increasing thepower of the lens) but remains generally spherical. The deflectionelement deflects more quickly than the anterior element, until theyengage, as shown in FIG. 14.

As the pressure in the active channel continues to increase, theactuator continues to deflect in the anterior direction. Because thedeflection element is in contact with the anterior element, furtherdeflection element movement deflects the anterior element. Because ofthe size of the deflection element relative to the anterior element, thefluid in passive chamber 314 redistributes and creates an asphericeffect in anterior element 302, as shown in FIG. 15. This furtherincreases the power of the IOL for a smaller aperture.

This embodiment allows for a lower power change rate at relatively lowstimulus levels (FIG. 14) and a higher power change rate at higherstimulus levels (FIG. 15). The anterior element can remain generallyspherical when under a low stimulus and becomes aspherical when under ahigher stimulus.

One or more of the optic components can be made from suitable polymericmaterials. In one embodiment all of the optic components are made ofsubstantially the same polymeric material. Exemplary polymericcompositions that can be used for the optic portion include thosedescribed in commonly owned, co-pending U.S. patent application Ser. No.12/034,942, filed Feb. 21, 2008, and U.S. patent application Ser. No.12/177,720, filed Jul. 22, 2008.

The haptics are disposed on the lens such that when implanted in thelens capsule, the haptics deform in response to the capsule shapechanges. The capsule changes shape as the zonules apply or relax forceson the capsule in response to ciliary muscle relaxation or contraction.

In one embodiment the IOL is a fluid-driven accommodating IOL which isadapted to move fluid between an interior chamber in the haptics and theoptic portion in response to ciliary muscle movement to cause a changein the power of the lens. In a particular embodiment the fluid is movedto the optic portion as the ciliary muscles begin to contract, causingthe zonules to relax the forces applied to the capsule. As the zonulesrelax the forces, the capsule and/or the optic portion compress thehaptic, resulting in fluid moving to the optic portion and an increasein fluid pressure in the optic portion. The fluid movement causes adeflection in an anterior element of the lens, which increases the powerof the lens.

FIG. 16 shows the cross sections of an exemplary haptic 50 beingcompressed between the lens capsule 52 and the optic portion 54 bycompressive force “B”. Because the fluid is moved between the haptic andoptic portion as the haptic is compressed, the responsiveness of thehaptic to the change in forces from the capsule is important in creatingan energy efficient IOL. It is generally desirable to transfer energy asefficiently as possible from the forces applied or relaxed on thecapsule to the anterior element displacement. The overall shape of thehaptic, and perhaps more importantly, the cross-sectional shape of thehaptic, can influence how efficiently fluid is transferred between thehaptic and the optic portion in response to ciliary musclerelaxation/contraction. It is desirable to obtain a greater responsefrom the haptic in response to a change in force on the lens capsule. Itis also desirable to have a haptic/lens system that responds quickly tochanges in capsule state.

FIGS. 17-20 show exemplary haptic shapes and cross sections. FIG. 17shows a haptic with an elliptical cross section, with a height H greaterthan width W. FIG. 18 shows a haptic with a “D” shaped cross section.FIG. 19 shows an alternative haptic shape with a circular cross section.FIG. 20 illustrates a haptic with a flat oval cross section.

Other shapes and/or cross sections can also be used to provide for amore responsive haptic. In addition, the haptic may be comprised of aplurality of sections each with differing polymeric compositions, whichmay allow one section of the haptic to be stiffer than a differentsection, which could help increase the responsiveness of the haptic.Exemplary polymeric compositions that can be used for the hapticsinclude those described in U.S. patent application Ser. No. 12/034,942,filed Feb. 21, 2008, and U.S. patent application Ser. No. 12/177,720,filed Jul. 22, 2008.

Wall thicknesses can also be varied in a given cross-section to allowlocalized movement and to increase efficiency. FIG. 21 is a crosssectional view showing the exemplary cross section of a haptic. Hapticheight 260 is between about 3.0 mm and about 3.4 mm. Haptic width 262 isbetween about 1.2 mm and about 2.0 mm. Haptic wall thickness 264 isbetween about 0.1 mm and about 0.3 mm. These dimensions are merelyexemplary and are not intended to be limiting.

In some embodiments the haptic shape may be adapted to more naturallymate with the curved equatorial portion of the lens capsule in andisaccommodated state, or to better compliment the corresponding matingsurface of the lens. This may help increase the responsiveness of thehaptic and decrease the amount of lost movement due to “dead space”between the haptic and the capsule. FIG. 19 is an example of this. FIG.22 shows an additional cross sectional design of haptic 300, in additionto the capsule in accommodated and disaccommodated configurations.

FIG. 23 shows an alternative haptic design comprising bellows 501 alongone side of haptic 500. The haptic can be attached to the optic portionusing any of the methods described or referenced herein. Haptic 500 canalso include a reinforcing element 502 along the peripheral side of thehaptic to ensure the haptic contacts the capsule bag equator. Thereinforcing element can be, for example, a reinforced nitinol wire(metal) or monofilament (plastic).

FIG. 24 is a top view showing IOL 512 in a disaccommodated state(natural relaxed state) before implantation relative to exemplarycapsular bag 506. Haptics 500 have a diameter of about 10 mm. The opticportion has a diameter of about 6 mm. When implanted in the capsularbag, the capsular bag relaxation causes pressure to be exerted on thehaptics, thus bending the haptics. The bellows provide for greatervolume reduction in the haptics, which displaces more volume of fluid tothe optic portion.

Additional exemplary accommodating IOLs that can incorporate any of thefeatures described herein are described in commonly owned U.S.Provisional Application No. 60/433,046, filed Dec. 12, 2002; U.S. Pat.Nos. 7,122,053; 7,261,737; 7,247,168; and 7,217,288; U.S. patentapplication Ser. No. 11/642,388, filed Dec. 19, 2006; and U.S. patentapplication Ser. No. 11/646,913, filed Dec. 27, 2006, the disclosures ofwhich are hereby incorporated by reference in their entirety.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. An accommodating intraocular lens, comprising: anoptic that includes a deformable anterior element that includes ananterior most location of the optic, the deformable anterior elementadapted to deform to change the power of the accommodating intraocularlens, a posterior element that includes a posterior most location of theoptic, and an optic fluid chamber; a first haptic that is secured to theoptic and that extends radially outward from the optic, the first haptichaving an anterior portion that extends further in the anteriordirection than the anterior most location of the optic; and a secondhaptic that is secured to the optic and that extends radially outwardfrom the optic, the second haptic having a posterior portion thatextends further in the posterior direction than the posterior mostlocation of the optic, the first and second haptic each comprising amaterial and a configuration such that they are adapted to deform inresponse to capsular bag reshaping.
 2. The accommodating intraocularlens of claim 1, wherein the first and second haptics each have a fluidchamber in fluid communication with the optic fluid chamber.
 3. Theaccommodating intraocular lens of claim 1, wherein the first haptic alsoextends further in the posterior direction than the posterior mostlocation of the optic.
 4. The accommodating intraocular lens of claim 1,wherein the second haptic also extends further in the anterior directionthan the anterior most location of the optic.